Organic and mineral imprints in fossil photosynthetic mats of an East Antarctic lake
Lacustrine microbial mats in Antarctic ice-free oases are considered modern analogues of early microbial ecosystems as their primary production is generally dominated by cyanobacteria, the heterotrophic food chain typically truncated due to extreme environmental conditions, and they are geographical...
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ftnerc:oai:nora.nerc.ac.uk:507876 2024-02-11T09:57:27+01:00 Organic and mineral imprints in fossil photosynthetic mats of an East Antarctic lake Lepot, K. Compère, P. Gérard, E. Namsaraev, Z. Verleyen, E. Tavernier, I. Hodgson, D. A. Vyverman, W. Gilbert, B. Wilmotte, A. Javaux, E. J. 2014-09 http://nora.nerc.ac.uk/id/eprint/507876/ https://doi.org/10.1111/gbi.12096 unknown Wiley Lepot, K.; Compère, P.; Gérard, E.; Namsaraev, Z.; Verleyen, E.; Tavernier, I.; Hodgson, D. A. orcid:0000-0002-3841-3746 Vyverman, W.; Gilbert, B.; Wilmotte, A.; Javaux, E. J. 2014 Organic and mineral imprints in fossil photosynthetic mats of an East Antarctic lake. Geobiology, 12 (5). 424-450. https://doi.org/10.1111/gbi.12096 <https://doi.org/10.1111/gbi.12096> Publication - Article PeerReviewed 2014 ftnerc https://doi.org/10.1111/gbi.12096 2024-01-19T00:03:13Z Lacustrine microbial mats in Antarctic ice-free oases are considered modern analogues of early microbial ecosystems as their primary production is generally dominated by cyanobacteria, the heterotrophic food chain typically truncated due to extreme environmental conditions, and they are geographically isolated. To better understand early fossilization and mineralization processes in this context, we studied the microstructure and chemistry of organo-mineral associations in a suite of sediments 50–4530 cal. years old from a lake in Skarvsnes, Lützow Holm Bay, East Antarctica. First, we report an exceptional preservation of fossil autotrophs and their biomolecules on millennial timescales. The pigment scytonemin is preserved inside cyanobacterial sheaths. As non-pigmented sheaths are also preserved, scytonemin likely played little role in the preservation of sheath polysaccharides, which have been cross-linked by ether bonds. Coccoids preserved thylakoids and autofluorescence of pigments such as carotenoids. This exceptional preservation of autotrophs in the fossil mats argues for limited biodegradation during and after deposition. Moreover, cell-shaped aggregates preserved sulfur-rich nanoglobules, supporting fossilization of instable intracellular byproducts of chemotrophic or phototrophic S-oxidizers. Second, we report a diversity of micro- to nanostructured CaCO3 precipitates intimately associated with extracellular polymeric substances, cyanobacteria, and/or other prokaryotes. Micro-peloids Type 1 display features that distinguish them from known carbonates crystallized in inorganic conditions: (i) Type 1A are often filled with globular nanocarbonates and/or surrounded by a fibrous fringe, (ii) Type 1B are empty and display ovoid to wrinkled fringes of nanocrystallites that can be radially oriented (fibrous or triangular) or multilayered, and (iii) all show small-size variations. Type 2 rounded carbonates 1–2 μm in diameter occurring inside autofluorescent spheres interpreted as coccoidal bacteria may ... Article in Journal/Newspaper Antarc* Antarctic Antarctica East Antarctica Natural Environment Research Council: NERC Open Research Archive Antarctic East Antarctica Lützow-Holm Bay ENVELOPE(38.000,38.000,-69.500,-69.500) Skarvsnes ENVELOPE(39.667,39.667,-69.467,-69.467) Geobiology 12 5 424 450 |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
unknown |
description |
Lacustrine microbial mats in Antarctic ice-free oases are considered modern analogues of early microbial ecosystems as their primary production is generally dominated by cyanobacteria, the heterotrophic food chain typically truncated due to extreme environmental conditions, and they are geographically isolated. To better understand early fossilization and mineralization processes in this context, we studied the microstructure and chemistry of organo-mineral associations in a suite of sediments 50–4530 cal. years old from a lake in Skarvsnes, Lützow Holm Bay, East Antarctica. First, we report an exceptional preservation of fossil autotrophs and their biomolecules on millennial timescales. The pigment scytonemin is preserved inside cyanobacterial sheaths. As non-pigmented sheaths are also preserved, scytonemin likely played little role in the preservation of sheath polysaccharides, which have been cross-linked by ether bonds. Coccoids preserved thylakoids and autofluorescence of pigments such as carotenoids. This exceptional preservation of autotrophs in the fossil mats argues for limited biodegradation during and after deposition. Moreover, cell-shaped aggregates preserved sulfur-rich nanoglobules, supporting fossilization of instable intracellular byproducts of chemotrophic or phototrophic S-oxidizers. Second, we report a diversity of micro- to nanostructured CaCO3 precipitates intimately associated with extracellular polymeric substances, cyanobacteria, and/or other prokaryotes. Micro-peloids Type 1 display features that distinguish them from known carbonates crystallized in inorganic conditions: (i) Type 1A are often filled with globular nanocarbonates and/or surrounded by a fibrous fringe, (ii) Type 1B are empty and display ovoid to wrinkled fringes of nanocrystallites that can be radially oriented (fibrous or triangular) or multilayered, and (iii) all show small-size variations. Type 2 rounded carbonates 1–2 μm in diameter occurring inside autofluorescent spheres interpreted as coccoidal bacteria may ... |
format |
Article in Journal/Newspaper |
author |
Lepot, K. Compère, P. Gérard, E. Namsaraev, Z. Verleyen, E. Tavernier, I. Hodgson, D. A. Vyverman, W. Gilbert, B. Wilmotte, A. Javaux, E. J. |
spellingShingle |
Lepot, K. Compère, P. Gérard, E. Namsaraev, Z. Verleyen, E. Tavernier, I. Hodgson, D. A. Vyverman, W. Gilbert, B. Wilmotte, A. Javaux, E. J. Organic and mineral imprints in fossil photosynthetic mats of an East Antarctic lake |
author_facet |
Lepot, K. Compère, P. Gérard, E. Namsaraev, Z. Verleyen, E. Tavernier, I. Hodgson, D. A. Vyverman, W. Gilbert, B. Wilmotte, A. Javaux, E. J. |
author_sort |
Lepot, K. |
title |
Organic and mineral imprints in fossil photosynthetic mats of an East Antarctic lake |
title_short |
Organic and mineral imprints in fossil photosynthetic mats of an East Antarctic lake |
title_full |
Organic and mineral imprints in fossil photosynthetic mats of an East Antarctic lake |
title_fullStr |
Organic and mineral imprints in fossil photosynthetic mats of an East Antarctic lake |
title_full_unstemmed |
Organic and mineral imprints in fossil photosynthetic mats of an East Antarctic lake |
title_sort |
organic and mineral imprints in fossil photosynthetic mats of an east antarctic lake |
publisher |
Wiley |
publishDate |
2014 |
url |
http://nora.nerc.ac.uk/id/eprint/507876/ https://doi.org/10.1111/gbi.12096 |
long_lat |
ENVELOPE(38.000,38.000,-69.500,-69.500) ENVELOPE(39.667,39.667,-69.467,-69.467) |
geographic |
Antarctic East Antarctica Lützow-Holm Bay Skarvsnes |
geographic_facet |
Antarctic East Antarctica Lützow-Holm Bay Skarvsnes |
genre |
Antarc* Antarctic Antarctica East Antarctica |
genre_facet |
Antarc* Antarctic Antarctica East Antarctica |
op_relation |
Lepot, K.; Compère, P.; Gérard, E.; Namsaraev, Z.; Verleyen, E.; Tavernier, I.; Hodgson, D. A. orcid:0000-0002-3841-3746 Vyverman, W.; Gilbert, B.; Wilmotte, A.; Javaux, E. J. 2014 Organic and mineral imprints in fossil photosynthetic mats of an East Antarctic lake. Geobiology, 12 (5). 424-450. https://doi.org/10.1111/gbi.12096 <https://doi.org/10.1111/gbi.12096> |
op_doi |
https://doi.org/10.1111/gbi.12096 |
container_title |
Geobiology |
container_volume |
12 |
container_issue |
5 |
container_start_page |
424 |
op_container_end_page |
450 |
_version_ |
1790609745902567424 |